The subject of gradient-index optics dates from the 1850s. However, only in the last 10 years has it been possible to design lenses, manufacture materials, measure the properties, and fabricate finished lens elements. The current status of gradient-index optics is reviewed.
© 1980 Optical Society of America
Duncan T. Moore, "Gradient-index optics: a review," Appl. Opt. 19, 1035-1038 (1980)